SA and Victoria to swelter through remainder of long weekend

Victorians and South Australians are being urged to stay cool and hydrated amid extreme heat this long weekend.

Despite escaping an Australia Day scorcher, the Bureau of Meteorology said conditions on Sunday will be severe in South Australia with tops of 41 and 42 degrees forecast ahead of a cool change.

Meanwhile in Victoria's Mallee and north central region is expected to reach a maximum of 38 degrees on Sunday, as Mildura and Swan Hill are expected to reach temperatures in the low-40s.

Melbourne’s CBD is also expected to also reach a scorching 38 degrees.

"Important this weekend; keep cool, stay hydrated and protect yourself from the sun," Victorian Emergency Management Commissioner Craig Lapsley tweeted.

The weather is expected to remain hot, humid and hazy across Victoria for the rest of the weekend due to a high-pressure system over the Tasman Sea.

A cold front further south is not expected to reach Victoria until Sunday night before it moves across other parts of the state on Monday.

With AAP.